Non-paroxysmal atrial fibrillation mapping: characterization of the electrophysiological substrate using a novel integrated mapping technique

Europace. 2019 Aug 1;21(8):1193-1202. doi: 10.1093/europace/euz123.

Abstract

Aims: Clinical outcomes after radiofrequency catheter ablation (RFCA) remain suboptimal in the treatment of non-paroxysmal atrial fibrillation (AF). Electrophysiological mapping may improve understanding of the underlying mechanisms. To describe the arrhythmia substrate in patients with persistent (Pers) and long-standing persistent (LSPers) AF, undergoing RFCA, using an integrated mechanism mapping technique.

Methods and results: Patients underwent high-density electroanatomical mapping before and after catheter ablation. Integrated maps characterized electrogram (EGM) cycle length (CL) in regions with repetitive-regular (RR) activations, stable wavefront propagation, fragmentation, and peak-to-peak bipolar voltage. Among 83 patients (72% male, 60 ± 11 years old), RR activations were identified in 376 regions (mean CL 180 ± 31 ms). PersAF patients (n = 43) showed more RR sites per patient (5.3 ± 2.4 vs. 3.7 ± 2.1, P = 0.002) with faster CL (166 ± 29 vs. 190 ± 29 ms; P < 0.001) and smaller surface area of fragmented EGMs (15 ± 14% vs. 27 ± 17%, P < 0.001) compared with LSPersAF. The post-ablation map in 50 patients remaining in AF, documented reduction of the RR activities per patient (1.5 ± 0.7 vs. 3.7 ± 1.4, P < 0.001) and area of fragmentation (22 ± 17% vs. 8 ± 9%, P < 0.001). Atrial fibrillation termination during ablation occurred at RR sites (0.48 ± 0.24 mV; 170.5 ± 20.2 ms CL) in 31/33 patients (94%). At the latest follow-up, arrhythmia freedom was higher among patients receiving ablation >75% of RR sites (Q4 82.6%, Q3 63.1%, Q2 35.1%, and Q1 0%; P < 0.001).

Conclusion: The integrated mapping technique allowed characterization of multiple arrhythmic substrates in non-paroxysmal AF patients. This technique might serve as tool for a substrate-targeted ablation approach.

Keywords: Ablation; Atrial fibrillation; Electrophysiological substrate; High-density electroanatomical mapping; Persistent atrial fibrillation.

MeSH terms

  • Atrial Fibrillation* / diagnosis
  • Atrial Fibrillation* / physiopathology
  • Atrial Fibrillation* / surgery
  • Body Surface Potential Mapping* / instrumentation
  • Body Surface Potential Mapping* / methods
  • Cardiac Electrophysiology / methods
  • Catheter Ablation / methods*
  • Electrophysiologic Techniques, Cardiac* / instrumentation
  • Electrophysiologic Techniques, Cardiac* / methods
  • Electrophysiological Phenomena
  • Female
  • Humans
  • Male
  • Middle Aged
  • Perioperative Care / methods
  • Reproducibility of Results
  • Treatment Outcome